Rheostat.



' P. D. HALLOOK.

RHBOSTAT.

APPLICATION FILED DEC. 21, 1910.

Patented July 9, 1912.

INV NTOR amwW ATTORNEY WITNESSES:

"sirarns rnrnn'r orrion.

FLETCHER ID, EEJJLOCK, OIE EITTSBURGH, PENNSYLVANIA, ASSIGNOR T O WESTING- HQUSE ELECTRIC AND MANUFAGTURING COMPAIJY, A CORPORATION OF PENNSYL- VANIA.

Specification of Letters Eatent.

nnnosrar.

Patented July 9, 1912.

Application filed Becember 21, 1910. Serial No. 598,514.

'whioh the resistance conductor is wound upon the exterior of an. insulating tube.

The object of my invention is to providesupporting nicans for resistance elements of the character described which shall be simple and inexpensive in construction and shall-permit of expansion and contraction of the elements, as well as of rough handling of the rl costat, without subjecting the elements to undue strain and breakage. hen the present structure is used, the resistance conductor is also efiectively insulated from other parts.

Figure 1 of the accompanying drawing is a. plan and sectional view of a portion ot-a rheostat embodying my invention. Fig. 2 is a sectional view of a portion of another form of rheostat-that also embodies my invention, and Fig. 3 is a face view of one of the Washers that constitute parts of the supporting means. i

The resistance element in connection with which the present invention is employed consists of a porcelain or other suitable ins'ulating tube 1, on the exterior of which a resistance conductor 2 is wound and SE? cured. a any convenient manner.

.g. l, the resistance element is shown suspcnde between two members 3 and a, may be the sides or other parts of a at casing, and between which any donnber of the resistance elements may -ipende side'by side or in any other relation.

do: provided ,hy the red,

At each. endof theresistance ele- .nent is a sun ort COIlSlStlIl of a rod 5 that r:

iers 6-7 and 8-45, respectively, the washers 5 and being adgscent-tp the shouland the washers 8 and 9 being at or near the extremity of the rod. The washers are spaced apart by means of a sleeve 10 that surrounds the reduced portion of the rod, and the parts are secured together by riveting the end of the rod upon the Washer 9. The washers 6 and 8 are of slightly larger diameter than the inner circumference of the tube 1, and are resilient, being preferably provided with radial slots in order to render them somewhat more flexible than they would otherwise be. Thus, when the support is inserted in the end of the tube, thewashers (3 and 8 tightly engage the inner walls thereof and are rendered somewhat concave so that it is substantially impossible to withdraw the support from the tube. The provision of a plurality of spaced resilient washers upon the rod 5 is for the purpose of maintaining the rod substantially centrally -within the insulating tube. The washers 7 and 9 are of slightly less diameter than the inner diameter of the tube 1, and, being comparatively rigid, serve as limiting and reinforcing means for the resilient washers to prevent them from being bent beyond their elastic limits and given a permanent set. Thus, the resilient washers 6 and S, which support the tube directly cannot be rendered inactive or inef fective,: and the device is rendered more rigid, strong and durable by the presence of the washers 7 and 9.

It will be noted that the supporting de vice of the present invention is applied to the interior of the insulating tube, rather than to the exterior thereof, and is thus considerably removed from the. resistance conductor, the insulation of which is renments between the sidesor other parts of the. rll,ecstat5 it may be desirable; when insuiating supports are available, such as stone or other insuie'ting bases, to clamp the elements directly to such insulating parts. In Fig. 2, such a conscrnction is shown, the end of the insulating tube 1' being seated against a slate or other suitable insuieizing base and being retained in position by she supporting means described in con action with the other figures. The same construction may, of, course, be used also when the base is not composed of insulating material.

I claim as my invention:

1. The combination with a tube, of :1 supporting rod entendine' into its end, end a resilient member c'erried thereby and engaging the inner Wells ofthe tube.

2. The combination with a tube, of e supporting rod extending into its end, end

spaced resilient members carried thereby and engaging the inner 'We ils'of the tube.

3. The combination wither cube, 0:? a supporting rod extending into its end, eresiiient member. carried thereby and engaging the inner weiis of the tube, end a reinforcing member adjacent re the resiiieni mem- 4:. The combinationwi'eh a cube, 0% n sen porting rod extending into its end, spaced resiiient members carried thereby and engaging the iunorweiie of the cube,- end. reinforcing members 5. The combine e iube, oi e sunporiing rod extend ent. member cerriei my the inner Weiis of end engaging; Lee tube, end e member to which the projectin end of the rod secured.

6. The combine? porting rod extend resilient members cc *oite end, spaced thereby and engaging theinner Walls of the tube,

eldjscenii to the resilient I its end, reeiinf eh einbe, of e supgaging, the inner member tb which rod is secured.

7. The condiination with a tube, of a supporting rod extending into its end, a rcsi1ient member carried thereby. and engaging the inner Walls oi the tube, av reinforcing member adjacent to the resilient member, and a member to which the projecting end of the rod. is secured.

8. The combination with a tube, of a shpporting rod extending into its end, spaced resilient members carried thereby and enreinforcing members adjacent to the resilient members, and a member to which the projecting end of the rod is secured.

9. The combination with a tube, of a supporting rod extending into its end, and cl resiiicni; Washer upon the inner end of the rod iube,

end engaging the inner walls of the being of slightly greater Wsiis of the tube, and a the projecting end of the the said Washer diameter than the inner walls of the tube. 10. The combination with a tube, of a supporting rod extending into its end, a resiiient Washer upon the inner end of the red and engaging the inner wells of: the tube, .zhe said washer being of siightiy diameter than the inner webs of the tube, and o comparatively rigid Washer adjacent to the resilient Washer and of siighiiy less diameter then the inner Wells of the babe.

iestimony whereof, 1 have hereunto need. my name this 9th day of Dec.

snnrcnnn n. ermon.

copies of this patent may be eb'tsincd for five cents each,

by addressing the fiommissioncr of fPatems,

Wcehingicn, W.

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